Valve mechanism for compound engines



(No Model.)

F. M BITES. VALVE MECHANISM' FOR COMPOIUNDENGI-Ns.

Patented Jan. 18 1887.

fl/Iliff I ea" pw, wminmor u. c,

Unire STATES ArnNr erica.'

FRANCIS M. RITES, OF PITTSBURG, PENNSYLVANIA.

VALVE MECHANISNI FOR COMPOUND ENGINES.

SPECIFICATION forming part of Letters Patent No. 356,376, dated January18, 1887.

Application filed September 27, 1886. Serial No.2i4,592. (No model.) 4

To all whom, it may concern:

Be it known that I, FRANCIS M. BITES, residing at Pittsburg, in thecounty of Allegheny and State of Pennsylvania, a citizen of the UnitedStates, have invented or discovered acertain new. and useful Improvementin Valve Mechanism for Compound Engines, of which improvemcntthefollowing isaspeciication.

The object of my invention is to enable the admission of steam from thehigh-pressure to the low-pressure cylinder of a compound engine to beeffected by a single eccentric at the proper period of the piston-stroketo attain a high degree of expansion in the low-pressure cylinderwithout the corresponding undue compression in the high pressurecylinder incident to the operation of valve-gears as ordi,- narilyheretofore constructed. f

To this end my invention, generallystated, consists in the combination,with a steamen gine, of a sectional distribution-valve, the sections ofwhich govern the passage of steam through different ports, respectively,and which are independently coupled to the strap of a valve-operatingeccentric at different distances from the center thereof.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings, Figure 1 is avertical transverse sectionthrough a compound engine embodying my invention, taken at the center ofthe valve-chest; Fig. 2, a vertical longitudinal central section throughthe valve-chest, and Fig. 3 a horizontal section through the same at theline x x of Fig.'2.

The engine to which my improvement is herein shown as applied is of thevertical single-acting type, having a high-pressure cylinder, 1, and alow pressure cylinder, 2, of larger diameter, fixed side and side uponthe top of a crank caseor boX, 3, and fitted with pistons coupled byconnecting-rods in the ordinary manner to the pins of cranks set0ppositely or one hundred and twenty degrees apart on a crank-shaft, 5,rotating in end bearings in the crank-case 3. Steam is admitted to andexhausted from the high and low pressure cylinders by adistribution-valve reciprocated by an eccentric, 13, in a sleeve orbushing, 11, Xed in a valve-chest, 12, located between the cylinders andprovided With a se` ries of steam-supply ports, 17, communicating with asteam-supply passage, 16, to which the .main steam-pipe from the boileris connected,

a series of high-pressure ports, 18, above the supply-ports 17, saidhigh-pressure ports communicating with the piston-space of thehighpressure cylinder, a series of low-pressurek ports, 24, above thehigh-pressure ports communicating with-the pistonspace of thelowpressure cylinder, and a series of exhaustports, 25, above thelow-pressure ports, communicating with an exhaust-passage, 26 to whichan exhaustpipe,leading into the atmosphere or to a condenser, isconnected.

' The eccentric 13, which actuates the distribution-valve, ispreferably, as in the instance shown, mounted adjustably upon thecrankshaft, so as to be varied and controlled in position by acentrifugal governor of any suitable construction, the governorillustrated being similar to that which is set forth in an applicationfor Letters Patentfiled by me September 1, 1886, Serial No. 212,351, andnot constituting part of my present invention.

The distribution-valve by which admission separate and independentsections, 3 4, each having an upper and a lower piston connected by abody of smaller diameter, so as tol provide an annular space betweenthem for the passage of steam from one to another series of ports of thevalve-bushing 11, and both being coupled to the strap 19 of theeccentric 13, so as to be reciprocated therewith and thereby, but in,suchv manner, as presently to be described, that the valve-sections,while moving coincidently in the same direction, shall likewise haveindependent relative movements and exhaust are'effected is composed oftwo and different degrees of traverse, and are all ternately caused toapproach and recede from each other through a limited degree of traversein their upward and their downward movements respectively.

The admission of steam to the high-pressure cylinder is effected by theupper piston of the lower valve-section, 3, the exhaust of steam fromthe high-pressure cylinder to the lowpressure cylinder by thelowerpiston ofthe upper valve-section, 4, and the exhaust of steam from thelow-pressure cylinder to the exhaust- ICO passage 26, between the lowerand the upper pistons of the upper ValvesectiOn, 4. It results from suchconstruction and function of the valve-sections that if they be drawnmore closely together on their upward traverse and moved farther aparton their downward trav erse, and the upper section be given a greatertraverse than the lower section, a hetter portopening on both admissionand exhaust anda later exhaust will be attained for the lowpressurecylinder, thus affording a higher degree of expansion, and compressionwill he made later in both cylinders, all of which tend to a moreeconomical utilization of steam.

To impart the movements above referred to to the two valvesections fromthe eccentric 13, I provide the lbllowing mechanism: rEhe 'upper end ot'the eeccntriestrap 19 is caused to move in a substantially-vertical lineby being coupled to a fixed bearing, 29, on, the eranl case by meausofapair of links, 27. iournalcd at one end on a pin, 28, iu the bearinfr29, and

' at the other on a piu, '23, in the upper end of the eecentricfstrap.The lower valve-section, 3, is coupled by a pair of links, 22, to thepin 23, and a lateral projection, 141-, formed upon the upper` end ofthe eccentric-strap 19, substantiallyr at right angles to a line drawnfrom the center of the eccentric to the center of the pin 23, carries apin,2l,whieh is coupled by a link, 20, to a pin on the lower end ot' astem, 6, passing freely through the lower valveseetion, 3, and securedto the upper valve-sec tion, 4. The effect of such lateral connectionofthe upper valve-section to the eccentricstrap is toimpart to saidsection a movement corresponding to that which it would receive from aneccentric of greater throw and less angular advance than the eccentric13, as well as to retard in both directions the movement of the uppersection, l, relativelyto that of thelower section, 3, due to itsconnection with the strap in or substantially in line with the centerthereof, thereby giving an increased traverse to the section Irelatively to the section 3, and causing its distance from the section 3to be decreased on the upward stroke and increased on the downwardstroke of thc valve, the advantageous results of which difference oftraverse and variation of relative position have been hereinbeforestated. A

I claim as my invention and desire to secure by Letters Patentl. rlheeombiuatiomin a stearn-engine, of a distribution-valve composed of twoseparate and independent sections which govern, respectivel y, thepassage of steam through dift'en ent ports, and are independentlycoupled at different points to the strap of a singleoperating-eccentric, substantially as set forth.

2. The combination, in a steam-engine, of a distribution-valve composedof two separate and independent sections which govern, respcctiv ely,the passage ot'steam through different ports. a single operatingeccentric and strap, and link-connections in and ont of line,respectively, with the center oi" the eccentricstrap, and coupling thevalve-sections independently thereto, substantially as set forth.

3. The combination, with a compound engine having a hi gli-pressure anda low-pressure cylinder, of a valve-chest having a port or ports leadingto the high-pressure cylinder, a port or ports leading to thelow-pressure cylinder, and a port or ports leading tothe exhaust, adistribution-valve composed ot two separate and inde pendent sections,the high pressure section ot' which governs admission and exhaust ot'steam l to and from thehigh-pressure ports, an d the lowpressure sectionadmission of steam from the high-pressure to the lo\vpressure ports andexhaust from the low-pressure to the exhaustports, an operatingeccentric and eccentric- `strap, and links coupling the higlrpressure

